System and method for load based optimization in communication networks

ABSTRACT

Systems and methods for providing load based optimizations in communication networks are provided. A network device that provides network management and exchanges control messages with other network devices in the communication network can be modified to masquerade as a radio access transceiver to obtain radio access transceiver load information. The network device can be modified to include a radio-related interface and can communicate messages with the radio access transceivers to setup a radio access transceiver connection for exchange of load information. The radio access transceiver load information can then be used in the core network to provide optimizations for the loaded radio access transceivers. The optimizations can include modifying packet flows to decrease the bandwidth needed and switching one or more packet flows to another radio access transceiver.

RELATED APPLICATIONS

The present application is related to U.S. patent application Ser. No.13/333,381 filed Dec. 21, 2011, by Grayson, entitled “Systems andMethods for Load Balancing in Cellular Networks and Wireless Local AreaNetworks”, which is hereby incorporated by reference herein in itsentirety.

FIELD OF THE DISCLOSURE

This disclosure relates generally to systems and methods for providingload information from radio access transceivers to the core network andusing the load information to make decisions in the core network.

BACKGROUND

Wireless networks are telecommunication networks that use radio waves tocarry information from one node in the network to one or more receivingnodes in the network. Cellular telephony is characterized by the use ofradio cells that provide radio coverage for a geographic area, withmultiple cells arranged to provide contiguous radio coverage over alarger area. Wired communication can also be used in portions of awireless network, such as between cells or access points. Wirelesscommunication technologies are used in connection with many userequipment, including, for example, satellite communications systems,portable digital assistants (PDAs), laptop computers, and mobile devices(e.g., cellular telephones). Such devices can connect to a network(e.g., the Internet) as long as the user is within range of such awireless communication technology.

The increase in data traffic is straining wireless network operators'existing networks. The increase in data traffic can overload networkdevices in wireless networks, and it may even cause wireless networkservice disruptions. The demand for data over wireless networks is notexpected to slow, especially as mobile devices become more sophisticatedand as users become more dependent on mobile devices.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-2 illustrate a communication network including a long termevolution (LTE) topology in accordance with certain embodiments;

FIG. 3 shows a communication system with parallel networks in accordancewith certain embodiments;

FIG. 4 illustrates a signaling diagram to exchange load information inaccordance with some embodiments;

FIG. 5 illustrates a signaling diagram to exchange load information inaccordance with some embodiments;

FIG. 6 shows a communication system with parallel networks in accordancewith certain embodiments;

FIG. 7 illustrates a logical view of a network device in accordance withcertain embodiments;

FIG. 8 illustrates a logical view of a gateway that receives radio loadinformation and performs optimizations on packet traffic in accordancewith certain embodiments;

FIG. 9 illustrates a network device in accordance with certainembodiments; and

FIG. 10 illustrates a logical view of the software architecture of anetwork device in accordance with certain embodiments.

DESCRIPTION OF EXAMPLE EMBODIMENTS

Overview

In some embodiments, a method is disclosed that includes communicatingcontrol plane messages at a mobility management device, communicatingwith radio access transceivers over a radio-related interface from themobility management device, receiving radio access transceiver loadinformation over the radio-related interface from the radio accesstransceivers, and sending the radio access transceiver load informationto a gateway.

Example Embodiments

The increase in data traffic is straining wireless network operators'existing networks. This trend is likely to continue as the computingpower of mobile devices increases and more users switch to dataintensive tasks over wireless networks. Users with smart phones andwireless enabled computers use applications that frequently request dataand consume bandwidth. However, the load in some communication networkscan be non-uniform. By some accounts, typically less than five percentof a network's radio access transceiver sites are being utilized overfifty percent, where radio access transceivers provide wirelesscommunication capabilities with wireless devices. Load information fromthe radio access transceivers can be used by network devices to makedecisions that allow the network to operate more efficiently. Networkdevices at the core of the network do not receive load information fromthe radio access transceivers and are therefore unable to alter networkbehavior in the core network to increase network efficiency.

Once network devices are able to access load information, this loadinformation can be used to initiate a range of optimizations at thenetwork devices to manage the load on the network. For example, mobiledevices could be directed to a radio access transceiver that is lessloaded and can provide a better experience. Mobile devices may even bedirected to parallel communication networks such as femto networks orwireless local area networks. The mobile devices can be provided theloading information of the network in order to make a determination asto which network to attach. This can be useful for mobile devices thatmay not be able to determine network loading conditions withoutattaching to each of the various networks first. In addition, otheroperations on the network device can be provided in order to makecommunications with those radio access transceivers more efficient. Thiscan include a network device processing incoming packet data that isdestined to a loaded radio access transceiver. The processing caninclude compressing aspects of the packet flow or using more efficienttransmission protocols. Other load based changes can be made as well,such as offloading more traffic from the network device to the internetto avoid overloading the backhaul link.

FIG. 1 illustrates a communication system that supports load balancingin accordance with certain embodiments. FIG. 1 includes a number ofradio access technologies such as a 1×RTT transceiver 100, a high-ratepacket data (HRPD) transceiver 102, and an evolved high-rate packet data(eHRPD) transceiver 104, each of which can connect to an access network106. An evolved Node B (eNodeB) transceiver 108 is an LTE network radionetwork component that connects to an Evolved UMTS Terrestrial RadioAccess Network (E-UTRAN) 110. Other radio access technologies such asWireless Local Area Network (i.e., Wi-Fi), Femto, WiMAX, or any otherradio spectrum technology, can use a transceiver shown generally at 112to connect a user equipment (UE) 134 to the network using a broadband orother access network.

The access network 106 can communicate with an access gateway 116 thatimplements a combination of functionalities such as a packet dataserving node (PDSN), a HRPD serving gateway (HSGW), and a servinggateway (SGW). In operation, the PDSN functionality can be used with1×RTT 100, the HSGW functionality can be used with HRPD 102 and eHRPD104, and the SGW functionality can be used with the eNodeB 108. Theaccess gateway 116 can communicate with an anchor gateway 118, which canimplement a packet data network gateway (PGW) and a Home Agent (HA), anda mobility management entity (MME) 120. On the access network side, theanchor gateway 118 can also communicate with an evolved packet datagateway (ePDG) 122 that provides connectivity to the WLAN/Femto/othertransceiver 112. On the packet core side, the anchor gateway cancommunicate with the operator's IP service domain 124, the Internet 126,and IP multimedia subsystem (IMS) 128. An authentication, authorization,and accounting (AAA) server/home subscriber server (HSS) 130 cancommunicate with the access gateway 116, the anchor gateway 118, orboth.

The Home Subscriber Server (HSS) 130 can be a master user database thatsupports IMS network entities that handle calls. The HSS 130 storessubscription-related information (subscriber profiles), performsauthentication and authorization of the user, and can provideinformation about the subscriber's location and IP information. The HSS130 also maintains binding information on which gateway is currentlyserving a UE. Even when the UE 134 is detached from the network, the HSS130 maintains the binding information until the UE 134 re-attachesitself and updates the binding information. The AAA server 130 canprovide authentication, access control, and accounting to the network.The authentication can involve verification of the subscriber, theaccess control can involve granting or denying access to specificservices, and the accounting that can take place is the tracking of theuse of network resources by subscribers. Other servers, such as the HomeLocation Register (HLR) can be used in other embodiments. In certainembodiments, the AAA/HSS 130 can communicate with the access gateway 116for charging purposes.

The LTE communication network includes a PDN gateway (PGW) 118, aserving gateway (SGW) 116, an E-UTRAN (evolved-UMTS terrestrial radioaccess network) 110, and a mobility management entity (MME) 120. Theevolved packet core (EPC) of an LTE communication network includes theMME 120, SGW 116 and PGW 118 components. In some embodiments, one ormore EPC components can be implemented on the same gateway or chassis asdescribed below.

The SGW sits in the user plane where it forwards and routes packets toand from the eNodeB and PGW. The SGW also serves as the local mobilityanchor for inter-eNodeB handover and mobility between 3GPP networks. TheSGW routes and forwards user data packets, while also acting as themobility anchor for the user plane during inter-eNB handovers and as theanchor for mobility between LTE and other 3GPP technologies (terminatingS4 interface and relaying the traffic between 2G/3G systems and PGW).For idle state UEs, the SGW terminates the down link data path andtriggers paging when down link data arrives for the UE. The SGW managesand stores UE contexts, e.g. parameters of the IP bearer service andnetwork internal routing information. The SGW also performs replicationof the user traffic in case of lawful interception.

The PGW acts as the interface between the LTE network and other packetdata networks, such as the Internet or SIP-based IMS networks (fixed andmobile). The PGW serves as the anchor point for intra-3GPP networkmobility, as well as mobility between 3GPP and non-3GPP networks. ThePGW acts as the Policy and Charging Enforcement Function (PCEF), whichmanages Quality of Service (QoS), online/offline flow-based chargingdata generation, deep-packet inspection, and lawful intercept. The PGWprovides connectivity to the UE to external packet data networks bybeing the point of exit and entry of traffic for the UE. A UE may havesimultaneous connectivity with more than one PGW for accessing multiplepacket data networks. The PGW performs policy enforcement, packetfiltering for each user, charging support, lawful interception, andpacket screening. The PGW also provides an anchor for mobility between3GPP and non-3GPP technologies such as WiMAX and 3GPP2 standards (CDMA1× and EVDO). The PGW may also include processing capability which isable to compress aspects of the packet flow or enable the use of aplurality of transmission protocols which are characterized by havediffering computational complexity versus over the air interfaceefficiency.

The MME resides in the EPC control plane and manages session states,authentication, paging, mobility with 3GPP 2G/3G nodes, roaming, andother bearer management functions. The MME can be a standalone elementor integrated with other EPC elements, including the SGW, PGW, andRelease 8 Serving GPRS Support Node (SGSN). The MME can also beintegrated with 2G/3G elements, such as the SGSN and GGSN. Thisintegration can provide mobility and session management interworkingbetween 2G/3G and 4G mobile networks.

MME 120 is a control-node for the LTE access network. The MME isresponsible for UE tracking and paging procedures includingretransmissions. MME 120 handles the bearer activation/deactivationprocess and is also responsible for choosing the SGW for a UE at theinitial attach and at time of an intra-LTE handover. The MME alsoauthenticates the user by interacting with the HSS 130. The MME alsogenerates and allocates temporary identities to UEs and terminatesNetwork Access Server (NAS) signaling. The MME checks the authorizationof the UE to camp on the service provider's Public Land Mobile Network(PLMN) and enforces UE roaming restrictions. The MME is the terminationpoint in the network for ciphering/integrity protection for NASsignaling and handles the security key management. Lawful interceptionof signaling is also supported by the MME. The MME also provides thecontrol plane function for mobility between LTE and 2G/3G accessnetworks with the S3 interface terminating at the MME from the SGSN (notshown). The MME also terminates the S6a interface towards the home HSSfor roaming UEs.

The ePDG/HeNB 122 is responsible for interworking between the EPC andfixed untrusted non-3GPP access technologies such as a WLAN, WiMAX, LTEmetro, and femtocell access networks. The ePDG/HeNB 122 can useIPSec/IKEv2 to provide secure access to the EPC network. Optionally, theePDG/HeNB 122 can use Proxy Mobile IPv6 (PMIPv6) to interact with thePGW when the mobile subscriber is roaming in an untrusted non-3GPPsystem. The ePDG is involved in tunnel authentication and authorization,transport level packet marking in the uplink, policy enforcement ofQuality of Service (QoS) based on information received viaAuthorization, Authentication, Accounting (AAA) infrastructure, lawfulinterception, and other functions.

FIG. 2 illustrates a communication system with parallel networks inaccordance with legacy universal mobile telecommunications systems(UMTS) network devices in accordance with certain embodiments. Thelegacy transceivers include base transceiver station (BTS) 200 and NodeBtransceiver 202. The BTS 200 can communicate with a GSM EDGE RadioAccess Network (GERAN) 204 and the NodeB 202 can communicate with a UMTSterrestrial radio access network (UTRAN) 206. The serving GPRS supportnode (SGSN) can be implemented on a gateway 208 with a mobilitymanagement entity (MME). The GERAN 204 can communicate through the SGSNfunctionality on gateway 208 to serving gateway (SGW) 212 or gatewayGPRS support node (GGSN)/PGW 214. UEs 134 can receive data service via atrusted WLAN network.

In some embodiments, the load information can be transferred to networkdevices residing in the control plane of the network. For example,network devices such as the mobility management entity (MME), the SGSN,and the Home Agent (HA). These mobility management devices can beinvolved in the process of assigning resources, managing communicationsessions, and managing mobility of user equipment. The problem is thatthese mobility management devices may not be able to receive loadinformation because of their placement in the network and the interfacesthat are setup for the mobility management devices. The load informationcan include radio access transceiver load information such astransmitter load, available bandwidth, channel usage, transmitter usage,power consumption, memory consumption, and number of user equipmentattached.

The load information can be transferred to the mobility managementdevice by adding an interface to the mobility management device toretrieve the load information. The interface can provide communicationwith the radio access network, such as eNodeBs and nodeBs. Generally, anEvolved Universal Terrestrial Radio Access Network (E-UTRAN) is exposedto cell load information. This load information can be communicatedusing an interface used to communicate between network devices in theradio access network. For example, the X2 interface can be used. The X2interface is used to communicate between eNodeBs in LTE networks.

Since the interface is a radio-related interface, the mobilitymanagement device is modified to be able to communicate using thisradio-related interface. The radio-related interface can be the X2interface or any other applicable radio access transceiver to radioaccess transceiver interface that allows the mobility management deviceto communicate with the radio access transceiver as if it were a radioaccess transceiver itself. The radio access network equipment whencommunicating with a mobility management device in the core networkwould think that the mobility management device was another radio accessnetwork component. The mobility management device can follow many of theinterfaces' messaging protocols. In doing so, the mobility managementdevice masquerades or impersonates a radio access network transceiversuch as an eNodeB. The mobility management device can then use theinterface to setup a connection or session with one or more radio accessnetwork transceivers to regularly receive load information. The loadinformation can be received periodically or based on events so that themobility management device can track the current load of various networkdevices in the radio access network.

In some embodiments, the mobility management device, such as an MME, isable to establish X2 signaling connections with the eNodeBs that itcontrols. The MME uses the X2 signaling to get radio load informationfrom the eNodeB. The MME can signal to the eNodeBs that it is utilizingthe physical resource block (PRB) used by the eNodeB. The eNodeB canthen signal physical resource block load information over the X2interface to the MME. The MME can store the physical resource block loadinformation and determine from the physical resource block the load ofthe eNodeB. In certain embodiments, X2 interface signaling exchanges canbe used to collect the information used to determine the loadinformation. The MME can then monitor the load information and setupthresholds or algorithms to determine when changes are made based on theload information. The MME can then signal other devices in the corenetwork such as gateways that include packet flows to the impactedeNodeBs. The MME can also trigger modifications to packet flows that aredestined to the impacted eNodeBs.

The gateway can use the information communicated from the mobilitymanagement device to perform operations on the packet flows. Theseoperations include video optimization, TCP optimization, HTTPoptimization, or other techniques on the packet flow being carried bythe loaded radio network transceiver. In particular, these packet flowoptimization techniques are generally characterized as consumingadditional computational capabilities to operate and more generally, thedegree of computational requirements can be related to the degree ofoptimization. For example, video optimization techniques may includetrans-rating (changing bit rates without changing videoformats—typically using the least computation resources), trans-wrapping(changing the format without having to re-encode the video content whichuses substantial computational resources) or trans-coding (the fullre-encoding of the source video data which is most computationallyexpensive of the three in this example). The optimization techniques canalso involve header compression or other techniques to reduce the loadon the radio access transceivers.

In some embodiments, the MME can signal an SGW using the S11 interfaceregarding the loading conditions. The signaling can include instructionsto address loading, the loading information, radio transceiverinformation that is impacted by loading conditions, or packet flowinformation that is impacted by loading conditions. The signaling may beproprietary signaling that includes PDP context information or otheridentifying information so that the packet flows can be identified. Thisidentifying information can include IP addresses. The IP addresses canbe obtained by examining the IP address from which the load informationwas received and the IP address used the radio transceiver to originateGTP-U payload packets.

In certain embodiments, the SGW can signal a PGW using the S5 interfaceregarding the loading conditions. The signaling can include instructionsto address loading, the loading information, radio transceiverinformation that is impacted by loading conditions, or packet flowinformation that is impacted by loading conditions. The signaling may beproprietary signaling such as vendor specific messaging or informationelements. The SGW can pass the load information onto the PGW in order totrigger the PGW to selectively apply optimization techniques to packetflows. Optimization techniques can be resource intensive to the gateway,so selective application of the techniques based on loading informationprovides a way to devote resources to the packet flows and radiotransceivers that will benefit from the optimizations. In someembodiments, the mobility management device can send the loadinformation or instructions directly using the Gn/Gp interface to PGW orGGSN. Other methods such as tunneling to the gateway or working throughanother device such as a PCRF can be used as well.

The mobility management device can communicate with the radiotransceiver by discovering the radio transceivers and then requestingload information over the radio interface. In the X2 interface, theeNodeBs can be configured to automatically discover one another andsetup signaling between neighbors to manage mobility and share loadinginformation. An MME can use this process to establish a signalingrelationship with each of the eNodeBs the MME is servicing to obtainload information from the eNodeBs. The MME is in communication with theeNodeBs that it is servicing or managing through the S1-MME interface.Through this interface the MME can obtain information about the eNodeBssuch as their identity and location. The MME can then use the identityinformation about eNodeBs to establish an X2 connection. The MME cansend the eNodeB an X2 message to indicate that the MME is in the sameresource block and then solicit radio resource status messages from thateNodeB. Once the eNodeB receives from the MME that it is in the sameresource block and the MME is requesting radio resource status updates,the eNodeB will send the MME the requested information. In this way, theMME is pretending to be a peer eNodeB, when in fact it is not.

Since the eNodeB thinks that the MME is in fact an eNodeB, the MME mayconfigure the signaling relationship to avoid being selected as acandidate for a handover. The MME can send the eNodeB over the X2interface a Handover Preparation Failure message in response to HandoverRequest message from the eNodeB. The MME can also send in an ENBConfiguration Update message an indication that the spoofed eNodeB hasbeen powered down. As such, the spoofed eNodeB will not be selected fora handover avoiding potential problems.

FIG. 3 illustrates a signaling diagram to exchange load information inaccordance with certain embodiments. FIG. 3 includes user equipment (UE)134, eNodeB (eNB) 108, MME 308, SGW 306, and PGW 304. MME 308 caninclude any applicable mobility management device such as MME 120 andMME 208. SGW 306 can include any applicable serving gateway includingSGWs 212 and 116. PGW 304 can include any applicable PDN gatewayincluding PGWs 118 and 214. In step 310, eNodeB 108 and MME 308 exchangeS1 messaging on the S1-MME interface. The S1 messaging between eNodeB108 and MME 308 can be used to determine the identity of the eNodeB andsetup procedures at the various eNodeB communicating with MME 308. Onceconfigured, MME 308 can send paging requests and other control planemessages to eNodeB 108. The MME 308 can use the information it hasregarding eNodeB to spoof an eNodeB for the purposes of obtaininginformation from the eNodeB.

In step 312, the MME 308 sends an X2 setup request message to eNodeB108. The X2 setup request message can include configuration informationto setup connection signaling between the MME and the eNodeB. In the X2setup request message, the MME informs the eNodeB that the MME andeNodeB are eNodeB neighbors. Since the MME and eNodeB are identified asneighbors, the X2 interface allows sharing of information. The MME canalso instruct the eNodeB that they are sharing the same resource blocksuch as a physical resource block (PRB). In step 314, the eNodeB 108sends an X2 setup response message to MME 308. The X2 setup responsemessage includes information such as neighboring cells and otherinformation that exchanged to provide application level configurationdata used between two eNodeBs to interoperate over the X2 interface. TheMME may discard this information or store it for later use.

In step 316, the MME 308 sends an X2 resource status request message toeNodeB 108. The resource status request message is used by an eNB torequest the reporting of load measurements to another eNB. The eNodeB108 upon receiving the resource status request message from the MME 308can initiate the requested measurement according to parameters set inthe message. The MME 308 can request a variety of information in theresource status request message including the radio resource status, theTNL (transport network load) load, the hardware load, the compositeavailable capacity group, and ABS (almost blank subframe) status. TheMME can also indicate the requested reporting periodicity from theeNodeB, which will set the time interval between subsequent measurementreports.

In step 318, the eNodeB 108 sends an X2 resource state response messageto MME 308. The resource status response message is used by the eNodeBto provide the various load information requested by the other eNB. TheeNodeB 108 can provide for each cell information including the radioresource status, the 51 TNL (transport network load) load, the hardwareload, the composite available capacity group, and ABS (almost blanksubframe) status. The MME may use an algorithm to combine the separateload information provided by the eNodeB 108 into a composite loadinformation. The MME can use the load information received from theeNodeB and/or the composite load information to determine the loadingconditions at the various eNodeBs. The composite load information can bea scalar value.

The MME 308 can use algorithms to determine when the loading reacheslevels that it makes sense for the MME 308 to take action. The algorithmcan include determining a scalar load value upon which it forwardsinstructions or load based information to other core network devices tomodify packet flows. The algorithm can also involve calculations basedon the various types of load information received by the MME. In someembodiments, the different types of loading information can triggerdifferent actions by the MME. For example, a high S11 TNL load cantrigger a different response than a high hardware load. The algorithmcan also be set to trigger different actions based on a combination ofdifferent loading factors present at the eNodeB. The MME can map usersto the eNodeB in order to provide user level information to othernetwork devices in the core network. The mapping of user information tothe eNodeB allows the MME to target packet flows that are headed to aneNodeB based on loading conditions. The MME can determine the mappingbased on the IP address of eNodeB and the users that communicating withthat IP address. In some embodiments the MME can send the eNodeB IPaddress to the gateway that is providing packet flow modification andthe gateway can modify packet flows based on detecting the eNodeB IPaddress.

In step 320, MME 308 sends SGW 306 a S5 message that is prompted by thereceipt of load information at MME 308 from eNodeB 108. The S5 messagecan include load information, IP address information, or instructionsregarding optimizations to perform on packet flows. The load informationcan be a scalar value that is included in an vendor specific attributeinformation element of an S5 message or in a proprietary message. Theload information can provide SGW with information regarding the loadingconditions present in the radio access network. The IP addressinformation can include the IP addresses of specific users in which toperform certain modifications to their packet flows or the IP address ofan eNodeB with certain loading characteristics. The instructionsregarding optimization to perform on packet flows can includeinstructions on how to selectively modify packet flows to alleviateloading conditions. In step 322, the SGW 306 sends PGW 304 a S11 messagethat is prompted by the receipt of the S5 message in step 320. The S11message can include load information, IP address information, orinstructions regarding optimizations to perform on packet flows.

In step 324, the PGW uses the information based on loading conditionssent from the MME 308 to selectively modify packet flows based onloading conditions. The modifications can include optimizations such asvideo optimization, TCP optimization, and HTTP optimization. In someembodiments, the MME may provide the PGW with the load information. ThePGWs in the core network of an operator likely have consistent rulessuch that the separate PGWs will react in the same way to the same loadinformation. For example, in GBR (guaranteed bit rate) handling, whenthe PGW is provided with load information of X, then every receiving PGWcan be operable to reduce GBR throughput by a percentage A. Whenprovided with load information of Y at the PGW, the PGW can be operableto reduce the GBR load by percentage B. In this way the coordination ofGBR bearers handled by different PGW can be accommodated in a fairmanner across the network of PGWs. This example is for GBR bearers, butthe same can be true for non-GBR bearers.

In other embodiments the PGW on receiving the signaled load informationfrom the MME 308, may be operable to store the information and delay theoperation of packet flow optimization 324 until a request for servicehas been received from UE 134. For example, subsequent to being signaledabout the eNodeB load information, the UE 134 may request the deliveryof a video using Adaptive Bite Rate technology by sending a request viaPGW 304. The PGW may identify the request as coming from a congestedcell and be operable to modify the video manifest file delivered fromthe video server to the UE 134. In one example, the PGW may removehigher rate versions of the video file from the manifest such that thehigher rate video streams cannot be accessed by the UE 134.

FIG. 4 illustrates a signaling diagram to exchange load information inaccordance with some embodiments. FIG. 4 includes user equipment (UE)134, eNodeB (eNB) 108, mobility management entity (MME) 308, server 410,and PDN gateway (PGW) 304. The server can be a policy charging and rulesfunction (PCRF), a video optimization server, a policy decisionfunction, a policy server, or communication server. The MME 308 can sendmessaging 412 to server 410 to initiate load information basedmodifications in the core network. After the MME 308 receives the radioaccess network load information, the MME can send messaging 412. The MMEcan use the S7 interface to communicate messaging 412 to a PCRF, whenserver 410 implements a PCRF. An S6 interface can be used to communicatefrom the MME to an Home Subscription Service (HSS), when server 410implements a HSS.

Server 410 can implement a PCRF when the server is responsible forpolicy and rules for user equipment and network devices in the network.The MME 308 can send policy instructions or load information to theserver 410 so that selective optimizations can be made in the corenetwork to radio access transceivers that are experiences certain levelsof loading. The server 410 can send messaging 414 to PGW 304 toimplement the optimizations on selected packet flows. The packet flowsthat are selected for modification can be those of user equipment 134attached to loaded eNB 108.

FIG. 5 illustrates a signaling diagram to exchange load information inaccordance with some embodiments. FIG. 5 includes user equipment (UE)134, eNodeB (eNB) 108, mobility management entity (MME) 420, and PDNgateway (PGW) 304. In some embodiments, the mobility management devicecan communicate directly with the gateway that can provide modificationsto selected packet flows. The MME can be co-located with an SGW or aSGSN in order to provide an interface to the PGW. The MME can also bemodified to include a direct interface to the PGW. In this embodiment,the MME can be enhanced to spoof an eNodeB to obtain load informationand a PGW or SGW to obtain direct access to a PGW. By spoofing otherdevices, the non-standard MME can use aspects of standardized interfacesto provide additional functionalities. The MME 420 can communicate withPGW 304 directly in step 422. This can be over the Sxx interface, aspecialized interface, or using standardized interface in anunanticipated way. The MME 420 can send the PGW 304 load information orinstructions so that PGW 304 can modify select packet flows in step 324.The modified packet flows are then communicated to eNodeB 108.

The load information that is obtained by the mobility management devicecan be used for other operations in the core network as well. This caninclude providing the load information to user equipment so that theuser equipment can decide between parallel networks. Additionally, thecore network devices can use the load information to try and shift userequipment to less loaded radio transceivers. For example, the corenetwork can suggest to one or more user equipment that they attach tonearby wireless local area network or femto network instead of thecellular radio access network. If the mobility management device canaccess the loading levels of parallel networks, than the mobilitymanagement device can steer applicable equipment to a less loaded radiotransceiver. This can benefit both the user equipment that moves to anew radio transceiver, but also those user equipment that remain on theloaded radio transceiver. The remaining user equipment can benefit fromthe less loaded conditions that occur once one or more user equipmentattach to a parallel network. Additionally, the user equipment can beprovided with information regarding loading at each of the parallelnetworks so that the user equipment can avoid joining a radiotransceiver that is already quite loaded.

FIG. 6 shows a communication system with parallel networks in accordancewith certain embodiments. FIG. 6 has a plurality of UEs 134A-134C; acellular network that includes a base station 108, for example, anevolved Node B (eNodeB) transceiver, a service area 220 of the basestation 108, an enhanced MME 120, and a base station load function(BSLF) 232; a wireless local area network (WLAN) that includes aplurality of access points (APs) 112A-112D, service areas 222A-222D ofthe plurality of APs 112A-112D, a WLAN control system 224 that includesa WLAN controller 228 and a mobility services engine (MSE) 226; acentral node called a location based congestion identification function(LBCIF) 234, which is configured to communicate with both the cellularnetwork system and the WLAN system; and an access network discovery andselection function (ANDSF) 230 in an Evolved Packet Core (EPC).

The BSLF 232 can be a part of cellular network's mobility unit, forexample, an MME 120. A cellular network is a radio network with multipletransceivers, where each transceiver provides communication to alocalized service area called a cell. The cellular network can includeLTE networks, HSPA+ networks, and UMTS networks, for example. The sizeof a cell can vary depending on the transceiver. A macro celltransceiver is typically used by service providers to provide coverageover about a five kilometer distance.

The ANDSF 230 is typically deployed as a stand-alone network device thatis accessible by UE 134. The ANDSF 230 can be co-located with the LBCIF234. In the case of a trusted WLAN, the WLC 228 is located in the WLANaccess network. If the trusted WLAN is operated by the cellular networkoperator, the WLC 228 can also be located in an MME 120. The WLC 228 andthe LBCIF 234 can communicate using a Simple Object Access Protocol(SOAP) or a Representational State Transfer (REST) protocol. Likewise,the BSLF 232 and the LBCIF 234 can communicate using the SOAP or theREST protocol, and the LBCIF 234 and the ANDSF 230 can communicate usingthe SOAP or the REST protocol.

The WLAN controller 228 can include a wireless LAN controller (WLC) 228.A WLC 228 can perform traditional roles of access points, such asassociation or authentication of wireless clients. APs 112A-112C, alsocalled access points, can register themselves with the WLC 228 andtunnel management and data packets to the WLC 228, which then switchesthe packets between the user equipment and the wired portion of thenetwork. WLC 228 can be in charge of the configuring the WLAN. WLC 228can provide configuration information to the APs 112A-112C so that theAPs 112A-112C can act as a wireless interface to the UEs 134.

The APs 112A-112C can be equipped with antennas that are configured totransmit and receive data. For example, the APs 112A-112C may transmitvideo or audio traffic and receive acknowledgements. In one embodiment,the APs 112A-112C can communicate in accordance with IEEE 802.11standard, including for example, IEEE 802.11n and 802.11k. The APs112A-112C may transfer video or other forms of high data rate trafficsuch as audio, or any other type of data traffic.

An ANDSF 230 is configured to assist UEs to discover non-3GPP networkssuch as WLAN or WiMax. To this end, the ANDSF 230 can be configured toprovide, to a UE, policy information regarding routing, mobility anddiscovery. The policy information can include an inter-system mobilitypolicy, which indicates network selection rules in case only one networkis available, (e.g., cellular or WLAN), an inter-system routing policy,which indicates network selection rules in case more than one network isavailable (e.g., both cellular and WLAN), and discovery information thatlists the networks that may be available to the UE and any candidateinformation about the networks. UEs can register with the ANDSF 230 toreceive service from the ANDSF 230.

In certain embodiments, an AP 112 can broadcast its data load conditionto UEs 134 (or all the UEs in the AP's service area) using a Quality ofService Basic Service Set (QBSS) load element. The QBSS load element isa part of beacon frames generated by APs and contains the data loadinformation associated with the APs. The QBSS load element can includethree parameters: station count, channel utilization, and availableadmission capacity. The station count can indicate the total number ofUEs currently associated with an access point. The channel utilizationrate can indicate the normalized value of the total channel utilizationwhich gives the percentage of the time the channel is sensed to be busyusing either the physical or virtual carrier sense mechanism of theaccess point. The available admission capacity can indicate the amountof time that can be used by explicit admission control. A user equipmentcan use the QBSS load element parameters to decide to which of theavailable access points to attach.

The communication system in FIG. 6 has a cellular network and a WLANoperating in parallel. Each network can have a plurality of serviceareas. A service area is often served by a wireless interface, such as abase station 108 or an AP 112. For example, a cellular network caninclude multiple service areas, each service area served by a basestation 108; a WLAN can include multiple service areas, each servicearea served by an AP 112. In certain embodiments, service areas indifferent networks can overlap. For example, in FIG. 3, the basestation's service area 220 overlaps with the APs' service areas222A-222C. If a UE 134A is in an area covered by both WLAN and acellular network, then the UE 134A can attach to one of the overlappingnetworks for network services.

In certain embodiments, the cellular network and the WLAN are configuredto collect their own network condition information. The networkcondition information can include information on the networkconfiguration and the network usage. For example, the network conditioninformation can include the data load information, which indicates theamount of data being handled by one or more of service areas in anetwork and/or the amount of additional data traffic that could behandled by one or more of service areas in a network. The networkcondition information can also include the geo-location of wirelessinterfaces in a network and a list of UEs currently served by one ormore service areas in a network and, if available, the geographicposition of the UEs. In certain embodiments, the network conditioninformation associated with a cellular network can be collected by aBSLF 232 in a MME 120. In certain embodiments, the network conditioninformation associated with a WLAN can be collected by the WLC 228 inthe WLAN control system 224.

The cellular network and the WLAN can share the collected networkcondition information with a central node 234. The central node 234, inturn, can retrieve the data load information from the received networkcondition information, and deliver the retrieved data load informationto UEs 134. There can be at least two ways to deliver the data loadinformation to UEs 134: (1) via a WLC 228 using an enhanced 802.11ksignaling or (2) via an ANDSF 230 using an IP signaling. For example, inthe first option, the central node 234 can deliver the data loadinformation to the WLC 228. In turn, the WLC 228 can deliver the dataload information to the AP 112. The AP 112 can subsequently broadcastthe data load information to the UEs in the AP's service area. Incertain embodiments, the AP 112 can broadcast the information as anenhanced-Quality of Service Basic Service Set (e-QBSS) load element. Inthe second option, the central node 234 can deliver the relevant dataload information to the ANDSF 230, and the ANDSF 230 can relay the dataload information to the UE 134. These options allow the UE 134 toreceive the network data load information of both the cellular networkand the WLAN without disconnecting from the currently attached network.

In certain embodiments, the central node 234 can deliver only relevantportion of the data load information to UEs 134. For a UE 134, therelevant data load information can include the data load information ofwireless interfaces that are capable of serving the UE 134. To determinewhich wireless interfaces can serve the UE 134, also called candidatewireless interfaces, the central node 234 can analyze the location ofwireless interfaces. For example, if a UE 134A is attached to an AP112A, the central node 234 can identify the serving AP 112A as one ofthe candidate wireless interfaces. To find additional wirelessinterfaces that can also serve the UE 134, the central node 234 can usethe location information of the serving AP 112A and the locationinformation of other wireless interfaces. For example, if a particularwireless interface is physically proximate to the serving AP 112A sothat the service are of a particular wireless interface includes that ofthe serving AP 112A, the central node 234 can identify the particularwireless interface as one of the candidate wireless interfaces. In someembodiments, if the service coverage of the particular wirelessinterface overlaps with that of the serving wireless interface, thecentral node 234 can identify that the particular wireless interface asone of the candidate wireless interfaces.

The UE 134 can use the received data load information to determine towhich wireless interface to attach. In other words, the UE 134 can usethe data load information to determine whether to remain attached to thecurrent wireless interface or to disconnect from the current wirelessinterface and attach to a wireless interface with less congestion and/orwith more available resources. In certain embodiments, the UE 134 canalso analyze additional information to decide to which wirelessinterface to connect. For example, the UE 134 can use one or more of thefollowing: the load condition associated with the wireless interfaces,the wireless signal strengths associated with the wireless interfaces,and a configuration status on the UE 134 indicating whether the UE 134favors the cellular network or the WLAN.

In certain embodiments, the central node 234 can periodically deliverthe data load information to UEs. This way, UEs can attach to a networkin a better network condition in substantially real-time. In otherembodiments, the central node 234 can deliver the data load informationin response to certain triggering events. For example, a central node234 can analyze the received network condition information to determineif any of the service areas in the parallel networks are congested orheavily utilized. If one of the service areas is congested or heavilyutilized, the central node 234 can identify the UEs currently served bythe congested service area and the wireless interfaces that can alsoserve the congested service area. Subsequently, the central node 234 cansend, to the identified UEs 134, the data load information associatedwith the identified wireless interfaces. This way, the identified UEscan disconnect from the congested service area, determine which of thewireless interfaces to connect to, and attach to the determined wirelessinterface.

In certain embodiments, the BSLF 232 can identify the physical locationof a base station 108. To identify the physical location of a basestation 108, the BSLF 232 (or the MME 120 hosting the BSLF 232) can senda location request to the base station 108. The location request can besent over an S1 interface using an S1 application protocol. Uponreceiving the location request, the base station 108 can obtain itspositioning information. In certain embodiments, the base station 108can use a global positioning system (GPS) to obtain its positioninginformation. Subsequently, the base station 108 can send a locationreply to the BSLF 232. The location reply can include the physicallocation identifier of the base station 108, which can be represented interms of GPS coordinates or geographic latitudes and longitudes. Thelocation reply can be sent over an S1 interface using an S1 applicationprotocol.

In certain embodiments, the BSLF 232 can also identify the physical,geographic location of UEs 134. For example, the BSLF 232 (or the MME120 hosting the BSLF 232) can send a UE positioning request to a basestation 108. The base station 108 can identify the UEs 134 attached tothe base station 108 and determine the location of the attached UEs 134.Then the base station 108 sends a UE positioning response to the BSLF232, including physical location identifiers of UEs 134 served by thebase station 108.

When the LBCIF or central node 234 receives the cellular networkcondition message and the WLAN condition message, the central node 234can decide whether to send the received data load information to one ormore UEs 134 or not. In certain embodiments, the central node 234 can beconfigured to send the received data load information to UEs 134periodically. To this end, the central node 234 can monitor a timer anddetermine whether a predetermine amount of time has passed since thecentral node 234 sent the data load information to the UEs 134.

In other embodiments, the central node 234 can be configured to send thereceived data load information in response to certain triggering events.For example, a central node 234 can analyze the received networkcondition information to determine if any of the service areas in theparallel networks are congested or heavily utilized. If one of theservice areas is congested or heavily utilized, the central node 234 canidentify the UEs currently served by the congested service area and thewireless interfaces that can also serve the congested service area.Subsequently, the central node 234 can send, to the identified UEs 134,the data load information associated with the identified wirelessinterfaces. This way, the identified UEs can disconnect from thecongested service area, determine which of the available wirelessinterfaces to connect to, and attach to the determined wirelessinterface.

In certain embodiments, if the UE 134 is attached to the cellularnetwork, the central node 234 may be aware of the physical location ofthe UE 134. For example, the central node 234 can receive the physicallocation of the UE 134 from the BSLF 232 as part of the networkcondition information. In this case, the central node 234 can identifycandidate wireless interfaces for the UE 134 by analyzing the locationof the UE 134, the location of wireless interfaces, and the average sizeof service areas for each type of wireless interfaces. If the physicaldistance between the UE 134 and a particular wireless interface is smallsuch that the UE 134 is within the service area of the particularwireless interface, the central node 234 can include the particularwireless interface as one of the candidate wireless interfaces. In otherembodiments, the central node 234 can identify the candidate wirelessinterfaces by querying the identity database. The central node 234 canquery the identity database to return all available wireless interfacesat the UE's location and use the returned result as the candidatewireless interfaces.

Once the central node 234 identifies candidate wireless interfaces, thecentral node 234 prepares data load information to send to the UE 134.Because the WLC 228 already has the data load information associatedwith the APs, the central node 234 can only prepare the data loadinformation associated with candidate base stations. In step 6, thecentral node 234 sends a cellular load message to the WLC 228. Thecellular load message includes the data load information associated withcandidate base stations 108.

In certain embodiments, the UE 134 can also analyze additional networkcondition information to decide to which wireless interface to connect.The additional network condition information can include one or more ofthe following: the load condition associated with the candidate wirelessinterfaces, the wireless signal strength associated with the candidatewireless interfaces, and a configuration status on the UE 134 indicatingwhether the UE 134 favors the cellular network or the WLAN. Theconfiguration status can be represented numerically. For example, theconfiguration status can be between 0 and 1, 0 indicating that the UE134 should always attach to a base station, and 1 indicating that the UE134 should always attach to an AP. The received data load informationand the additional network condition information can be combined togenerate a selection score using a selection algorithm. For example, theselection algorithm can have two inputs, the received data loadinformation and the additional network condition information, where thereceived data load information would adaptively modify the selectionalgorithm. For instance, the selection algorithm can include a functionwith hysteresis and the received data load information can determine thethreshold in the hysteresis function.

FIG. 7 illustrates a logical view of a network device 350 in accordancewith certain embodiments. The network device 350 can include a processor352, a memory 354, an interface 356, a functionality module 358, atransceiver interface module 360, a radio access load informationmanager 362. The network device 350 can implement a mobility managementdevice or any other applicable function using the hardware of thenetwork device. The functionality module 358 includes the logic that inconjunction with the processor 352 and memory 354 can implement thefunctionality. The functionality module can be implemented in softwareor hardware such as microcode, field programmable gate arrays, orapplication specific integrated circuits. The functionality moduleincludes the instructions and information that performs functionalitiesexpected of a particular network functionality. The functionalitiesimplemented by the functionality module 358 include an MME, an SGSN, anSGW, a PGW, a GGSN, a packet data serving node (PDSN), a home agent(HA), or any other applicable functionality.

An interface 356 can provide an input and/or output mechanism tocommunicate with other network devices. The interface 356 can implementthe X2 interface in conjunction with the transceiver interface module360. The interface 356 can provide a mechanism for communicating withnetwork devices such as the serving gateway (SGW), the PDN gateway(PGW), and the PCRF as well as radio access network devices such as theeNodeB. The interface 356 can be implemented in hardware to send andreceive signals in a variety of mediums, such as optical, copper, andwireless, and in a number of different protocols some of which may benon-transient. The transceiver interface module 360 can control how thenetwork device communicates over the interface 356.

The transceiver interface module 360 can support the communicationprotocols used by the functionality module 358. The transceiverinterface module 360 can be logic that includes the rules used tospecify how to form and read messages in a particular protocol and howto use the interface to communicate with another network device. Thetransceiver interface module 360 can be used to communicate using the X2protocol over interface 356. The transceiver interface module 360 caninclude modifications in the X2 protocol to allow a network devices suchas an MME to masquerade as an eNodeB for the purposes of obtaining radiotransceiver information.

The network device 350 can include a radio access load informationmanager 362. The radio access load information manager 362 can beimplemented as a module that uses memory 354 and runs on processor 352.The module can be implemented using logic that is implemented in anycombination of hardware or software. The radio access load informationmanager 362 can collect or track relevant information radio accessnetwork transceivers that can be later used in establishing an interfacewith the radio transceivers in the network. For example, the radioaccess load information manager 362 can track identity and locationinformation about radio transceivers in the access network. Thisidentity and location information can then be used by the transceiverinterface module 360 to establish a connection, such as an X2 interfaceconnection. In some embodiments, the radio access load informationmanager 362 can provide the information to the transceiver interfacemodule 360 in order to create an X2 message to indicate that the networkdevice is in the same resource block and to solicit radio resourcestatus messages from the radio transceiver.

When the transceiver interface module 360 receives radio resource statusupdate messages from radio transceivers, the transceiver interfacemodule 360 can send these to the radio access load information manager362. The radio access load information manager 362 can store the radiotransceiver load information in memory 354. The stored radio transceiverload information can be organized by the radio access load informationmanager 362 for use by other network devices in the network such asgateways. The collected load information from the radio transceivers canbe aggregated and organized and set to specific gateways in the corenetwork that are handling transmissions to the radio transceivers. Insome embodiments, the radio transceiver load information manager 362 cansend the information to transceiver interface module 360 to send overinterface 356 to one or more gateways in the core network.

The radio access load information manager 362 can also be setup to sendradio load information updates to gateways when specific events occur.For example, algorithms can be used in the radio access load informationmanager 362 to track the loading of the various radio transceivers andmessages are sent to the gateways only when certain thresholds orconditions are present. This can include when the loading of particulargateway reaches a certain value. The radio access load informationmanager 362 can also send instructions based on the loading value suchas to engage in packet data optimizations to that radio transceiver. Inthis way, the gateway can just receive messages when changes are madeand processing can be reduced. In some embodiments, the load informationis communicated to the gateway and the gateway determines how to respondto the load information.

The processor 352 can be one or more integrated circuits that are amultipurpose, programmable, clock-driven, register-based electronicdevice that accepts binary data as input, processes it according toinstructions stored in its memory, and provides results as output. Insome embodiments, the processor 352 can be constructed for a specificpurpose such as a network processing unit to perform specific tasks suchas inspecting received radio load information messages or processingcontrol plane messaging.

Memory 354 can be any type of computer readable medium such as randomaccess memory (RAM), programmable read-only memory (PROM), a fieldprogrammable gate array (FPGA), flash memory, optical disk drive, ormagnetic storage medium. The memory 354 can be used to store computerprograms or logic that can be run on processor 352. The memory 354 canalso store information such as data structures and other data that isused for collecting and providing load information.

FIG. 8 illustrates a logical view of a gateway that receives radio loadinformation and performs optimizations on packet traffic in accordancewith certain embodiments. In FIG. 8, gateway 850 includes a networkprocessing unit (NPU) 800, a packet director/NPU flow 802, a interfacemanager 804, sessions 806, a session manager module 808, an input/outputinterface 810, a process 812, a session cache 814, tasks 816, memory818, and a processor 820. Interface 810 includes one or more physicalconnections that can be either wired or wireless to communicateinformation to and from NPU 800. Session manager module 808 works withinterface 810 to provide signals to communicate information from NPU 800and to receive information from interface 810.

The NPU 800 receives electrical or optical signals on interface 810 fromthe access networks and transmits network information such as mediafragments, data packets, and mobile system information to mobiledevices. The NPU 800 is capable of performing deep packet inspection tomodify media protocols. Deep packet inspection includes a form of datapacket analysis that examines a data packet to obtain information as thedata packet is processed. The processor 820 can be one or moreintegrated circuits that are a multipurpose, programmable, clock-driven,register-based electronic device that accepts binary data as input,processes it according to instructions stored in its memory, andprovides results as output. In some embodiments, the processor 820 canbe constructed for a specific purpose such as a network processing unit800 to perform media protocol modification or another specific task.

Memory 818 can be any type of computer readable medium such as randomaccess memory (RAM), programmable read-only memory (PROM), a fieldprogrammable gate array (FPGA), flash memory, optical disk drive, ormagnetic storage medium. The memory 818 can be used to store computerprograms or logic that can be run on processor 820. The session manager808 can be implemented using a combination of hardware and software fortracking, managing, and processing a subscriber's data flows inconjunction with session 306. A session 306 can be dedicated to aparticular subscriber or user equipment to perform or monitor specificpacket flows or tasks 316. The session manager 808 can obtain subscriberinformation including radio transceiver load information on interface810. When radio transceiver load information is received or instructionsregarding the radio transceiver load information are received, thesession manager can direct the corresponding sessions to modify thepacket flows that are being handled by the session.

When a user equipment connects to the mobile wireless network through aradio access transceiver, a mobile subscriber session 806 can be createdbetween the user equipment and the gateway. In FIG. 8, the sessionmanager 808 manages a plurality of mobile subscriber sessions 806 andmay also authenticate the subscriber with a policy charging and rulesfunction (PCRF) through a mobile subscriber session 806 with the userequipment. The result is that the PCRF can use the interface 810 to sendmobile system information, including policy information and instructionsregarding QoS and services to be provided to the subscriber's data, tothe gateway. In some embodiments, the PCRF can also send radiotransceiver load information received from the mobility managementdevice. The session manager 808 can use this mobile system informationin managing sessions 806.

The gateway includes the capabilities to inspect packets with a networkprocessing unit and to modify packet information that is relevant forchanging the congestion at a congested radio transceiver. The gatewaycan use information obtained through deep packet inspection to correlatethe received radio access transceiver load information with a particularsubscriber and a specific packet flow. The process can work by receivingdata traffic on interface 810. The demux manager 804 manages theinterface 810 and sorts the data traffic for further processing. In someembodiments, the demux manager 804 provides a rough sorting of trafficinto different types of traffic based on shallow packet inspection. Thiscan include reviewing the outermost header information.

The demux manager 804 can then pass the data traffic to the networkprocessing unit 800 for further processing and deep packet inspection.The deep packet inspection can involve matching the higher layer packetheaders (e.g., layers 3-7) against criteria to direct and sort the datapackets. For example, deep packet inspection of the data traffic candetermine when a data packet includes packets for a specific radiotransceiver. In some embodiments, a packet director/NPU flow can besetup to sort out specific packet flows. A flow can be setup for sortingand further inspecting data packets. For example, a flow can be setup tocollect the packets that are received at the gateway that are going to acongested radio transceiver. Depending on the embodiment, multiple flowscan be setup in parallel to sort the packet flows on a per subscriberbasis or a flow can be setup to modify the packet flows from multiplesubscribers that are communicating from a particular radio transceiver.Once the packet flows are identified by the flow, then the packet flowscan be modified according to policy or rules in the gateway to ease theburden on the particular radio transceiver.

The flows can be setup to modify media requests (e.g., an adaptivebitrate request) according to rules that are configured when the flow issetup in the network processing unit. This can include setting therequest message to a specific bit rate for the requested fragment ofcontent. Setting the processor flow to modify the requests meetingcertain requirements is useful to minimize processing latency. Forexample, streaming a movie can result in the generation of a number ofmedia requests. Setting up the processor flow can allow the requests tobe modified shortly after receipt in hardware to correspond to networkpolicy parameters and subscriber preferences. The flow for a subscribercan be modified based on network level information to update themodifications made to received requests. The flow can be modified basedon performance conditions, policy settings, and subscriber conditions.The performance conditions can include fluctuations in the performanceof a wireless network.

User Equipment and Network Device

The UE 134 described above can communicate with a plurality of radioaccess networks using a plurality of access technologies and with wiredcommunication networks. The UE 134 can be a smart phone offeringadvanced capabilities such as word processing, web browsing, gaming,e-book capabilities, an operating system, and a full keyboard. The UE134 may run an operating system such as Symbian OS, iPhone OS, RIM'sBlackberry, Windows Mobile, Linux, Palm WebOS, and Android. The screenmay be a touch screen that can be used to input data to the UE 134 andthe screen can be used instead of the full keyboard. The UE 134 may havethe capability to run applications or communicate with applications thatare provided by servers in the communication network. The UE 134 canreceive updates and other information from these applications on thenetwork.

The UE 134 also encompasses many other devices such as televisions(TVs), video projectors, set-top boxes or set-top units, digital videorecorders (DVR), computers, netbooks, laptops, and any otheraudio/visual equipment that can communicate with a network. The UE 134can also keep global positioning coordinates, profile information, orother location information in its stack or memory. The UE 134 can have amemory such as a computer readable medium, flash memory, a magnetic diskdrive, an optical drive, a programmable read-only memory (PROM), and/ora read-only memory (ROM). The UE 134 can be configured with one or moreprocessors that process instructions and run software that may be storedin memory. The processor can also communicate with the memory andinterfaces to communicate with other devices. The processor can be anyapplicable processor such as a system-on-a-chip that combines a CPU, anapplication processor, and flash memory. The interfaces can beimplemented in hardware or software. The interfaces can be used toreceive both data and control information from the network as well aslocal sources, such as a remote control to a television. The UE 134 canalso provide a variety of user interfaces such as a keyboard, a touchscreen, a trackball, a touch pad, and/or a mouse. The UE 134 may alsoinclude speakers and a display device in some embodiments.

The radio-related interface and associated optimizations can beimplemented, at least in part, in one or more network devices in someembodiments. This network device can implement multiple and differentintegrated functionalities. In some embodiments, one or more of thefollowing functionalities can be implemented on the network deviceincluding a security gateway (SeGW), an access gateway, a GatewayGeneral packet radio service Serving Node (GGSN), a serving GPRS supportnode (SGSN), a packet data inter-working function (PDIF), an accessservice network gateway (ASNGW), a User Plane Entity (UPE), an IPGateway, a session initiation protocol (SIP) server, a proxy-callsession control function (P-CSCF), and an interrogating-call sessioncontrol function (I-CSCF), a serving gateway (SGW), and a packet datanetwork gateway (PDN GW), a mobility management entity (MME), a mobilityaccess gateway (MAG), an HRPD serving gateway (HSGW), a local mobilityanchor (LMA), a packet data serving node (PDSN), a foreign agent (FA),and/or home agent (HA).

In certain embodiments, the functionalities are provided by acombination of hardware and software in the network device. Generalpurpose hardware can be configured in the network device to provide oneor more of these specialized functionalities. The gateway can alsosupport sessions originated from a Femto base station, which wouldconnect to the gateway using a broadband network. A person orcorporation may use a Femto base station in a home or business tosupport one or more mobile nodes. The gateway can provide trigger basedtraffic management during a handoff from a Femto base station to a macrobase station, while maintaining traffic management for the mobile node.The offload gateway can be implemented as any combination of thefollowing including an xGSN, an xGW, an xGW-SGW, and an xGW-PGW.

In some embodiments the network device is implemented using a collectionof integrated circuit boards or cards. These cards include input/outputinterfaces for communication amongst each other, at least one processorfor executing instructions and running modules that are stored inmemory, and memory for storing data. The features of a network devicethat implements a gateway, in accordance with some embodiments, arefurther described below. FIG. 9 illustrates the implementation of anetwork device in accordance with some embodiments. The network device400 includes slots 402 for loading application cards and line cards. Amidplane can be used in the network device to provide intra-networkdevice communications, power connections, and transport paths betweenthe various installed cards. The midplane can include buses such as aswitch fabric 404, a control bus 406, a system management bus, aredundancy bus 408, and a time division multiplex (TDM) bus. The switchfabric 404 is an IP-based transport path for user data throughout thenetwork device implemented by establishing inter-card communicationsbetween application cards and line cards. The control bus 406interconnects the control and management processors within the networkdevice. The network device management bus provides management of systemfunctions such as supplying power, monitoring temperatures, boardstatus, data path errors, card resets, and other failover features. Theredundancy bus 408 provides transportation of user data and redundancylinks in the event of hardware failures. The TDM bus provides supportfor voice services on the system.

The network device supports at least four types of application cards: aswitch processor I/O card (SPIO) 410, a system management card (SMC)412, a packet service card (PSC) 414, and a packet accelerator card (notshown). Other cards used in the network device include line cards 466and redundant crossbar cards (RCC) 418. The line cards 416, when loadedin the network device, provide input/output connectivity to the networkand other devices, as well as redundancy connections. The line cards 416include interfaces to the network through Ethernet, Fiber Optic, and theother communication mediums. The redundant crossbar card (RCC) 418includes a non-blocking crossbar and connections to each of the cards inthe network device. This allows a redundant connection to be madethrough the redundant crossbar card 418 from any one card to any othercard in the network device. The SPIO card 410 serves as a controller ofthe network device and is responsible for such things as initializingthe network device and loading software configurations onto other cardsin the network device.

The system management card (SMC) 412 and switch processor card (notshown) are system control and management cards for managing andcontrolling other cards in the network device. The packet acceleratorcard (PAC) and packet service card (PSC) 414 provide packet processing,context processing capabilities, and forwarding capabilities among otherthings. The PAC and PSC 414 perform packet-processing operations throughthe use of control processors and a network processing unit. The networkprocessing unit determines packet processing requirements; receives andtransmits user data frames to/from various physical interfaces; makes IPforwarding decisions; implements packet filtering, flow insertion,deletion, and modification; performs traffic management and trafficengineering; modifies/adds/strips packet headers; and manages line cardports and internal packet transportation. The control processors, alsolocated on the packet accelerator card, provide packet-based userservice processing.

The operating system software can be based on a Linux software kerneland run specific applications in the network device such as monitoringtasks and providing protocol stacks. The software allows network deviceresources to be allocated separately for control and data paths. Forexample, certain packet accelerator cards and packet services cards canbe dedicated to performing routing or security control functions, whileother packet accelerator cards/packet services cards are dedicated toprocessing user session traffic. As network requirements change,hardware resources can be dynamically deployed to meet the requirementsin some embodiments. The system can be virtualized to support multiplelogical instances of services, such as technology functions (e.g., aSeGW PGW, SGW, MME, HSGW, PDSN, ASNGW, PDIF, HA, or GGSN).

The network device's software can be divided into a series of tasks thatperform specific functions. These tasks communicate with each other asneeded to share control and data information throughout the networkdevice. A task is a software process that performs a specific functionrelated to system control or session processing. Three types of tasksoperate within the network device in some embodiments: critical tasks,controller tasks, and manager tasks. The critical tasks controlfunctions that relate to the network device's ability to process callssuch as network device initialization, error detection, and recoverytasks. The controller tasks mask the distributed nature of the softwarefrom the user and perform tasks such as monitor the state of subordinatemanager(s), provide for intra-manager communication within the samesubsystem, and enable inter-subsystem communication by communicatingwith controller(s) belonging to other subsystems. The manager tasks cancontrol system resources and maintain logical mappings between systemresources.

Individual tasks that run on processors in the application cards can bedivided into subsystems. A subsystem is a software element that eitherperforms a specific task or is a culmination of multiple other tasks. Asingle subsystem can include critical tasks, controller tasks, andmanager tasks. Some of the subsystems that can run on a network deviceinclude a system initiation task subsystem, a high availability tasksubsystem, a recovery control task subsystem, a shared configurationtask subsystem, a resource management subsystem, a virtual privatenetwork subsystem, a network processing unit subsystem, a card/slot/portsubsystem, and a session subsystem.

The system initiation task subsystem is responsible for starting a setof initial tasks at system startup and providing individual tasks asneeded. The high availability task subsystem works in conjunction withthe recovery control task subsystem to maintain the operational state ofthe network device by monitoring the various software and hardwarecomponents of the network device. Recovery control task subsystem isresponsible for executing a recovery action for failures that occur inthe network device and receives recovery actions from the highavailability task subsystem. Processing tasks are distributed intomultiple instances running in parallel so if an unrecoverable softwarefault occurs, the entire processing capabilities for that task are notlost. User session processes can be sub-grouped into collections ofsessions so that if a problem is encountered in one sub-group users inanother sub-group will not be affected by that problem.

The architecture also allows check-pointing of processes, which is amechanism to protect the system against any critical software processesthat may fail. The self-healing attributes of the software architectureprotects the system by anticipating failures and instantly spawningmirror processes locally or across card boundaries to continue theoperation with little or no disruption of service. This uniquearchitecture allows the system to perform at the highest level ofresiliency and protects the user's data sessions while ensuring completeaccounting data integrity.

Shared configuration task subsystem provides the network device with anability to set, retrieve, and receive notification of network deviceconfiguration parameter changes and is responsible for storingconfiguration data for the applications running within the networkdevice. A resource management subsystem is responsible for assigningresources (e.g., processor and memory capabilities) to tasks and formonitoring the task's use of the resources.

Virtual private network (VPN) subsystem manages the administrative andoperational aspects of VPN-related entities in the network device, whichinclude creating separate VPN contexts, starting IP services within aVPN context, managing IP pools and subscriber IP addresses, anddistributing the IP flow information within a VPN context. In someembodiments, within the network device, IP operations are done withinspecific VPN contexts. The network processing unit subsystem isresponsible for many of the functions listed above for the networkprocessing unit. The card/slot/port subsystem is responsible forcoordinating the events that occur relating to card activity such asdiscovery and configuration of ports on newly inserted cards anddetermining how line cards map to application cards.

The session subsystem is responsible for processing and monitoring amobile subscriber's data flows in some embodiments. Session processingtasks for mobile data communications include: S1/S5/S8 interfacetermination for LTE networks, A10/A11 interface termination for CDMAnetworks, GSM tunneling protocol (GTP) termination for GPRS and/or UMTSnetworks, asynchronous PPP processing, IPsec, packet filtering, packetscheduling, Diffserv codepoint marking, statistics gathering, IPforwarding, and AAA services, for example. Responsibility for each ofthese items can be distributed across subordinate tasks (calledmanagers) to provide for more efficient processing and greaterredundancy. A separate session controller task serves as an integratedcontrol node to regulate and monitor the managers and to communicatewith the other active subsystem. The session subsystem also managesspecialized user data processing such as payload transformation,filtering, statistics collection, policing, and scheduling.

In providing emulation, as MIPv4 is received from a mobile node, thesession subsystem can setup a MIPv4 termination and setup a PMIPv6session towards the core network. A session manager can track themapping of the sessions and processing to provide the emulation andinter-working between the networks. A database can also be used to mapinformation between the sessions, and store, for example, NAI, HoA, AEinformation in some embodiments.

The network device allows system resources to be allocated separatelyfor control and data paths. For example, certain PACs/PSCs could bededicated to performing routing or security control functions whileother PACs/PSCs are dedicated to processing user session traffic. Asnetwork requirements grow and call models change, hardware resources canbe added to accommodate processes, such as encryption, packet filtering,etc., that require more processing power. FIG. 10 illustrates a logicalview of the software architecture of a network device in accordance withcertain embodiments. As shown, the software and hardware can bedistributed within the network device and across different circuitboards, processors, and memory. FIG. 10 includes a primary switchprocessor card (SPC)/system management card (SMC) 500 a, a secondarySPC/SMC 500 b, PAC/PSC 502 a-502 d, a communication path 504, and asynchronization path 506. The SPC/SMC 500 include a memory 508, aprocessor 510, a boot configuration 512, high availability tasks 514,resource manager 516, switch fabric control 518, and controller tasks520.

The SPC/SMC 500 manages and controls the network device including theother cards in the network device. The SPC/SMC 500 can be configured ina primary and secondary arrangement that provides redundancy andfailsafe protection. The modules or tasks running on the SPC/SMC 500 arerelated to network device wide control and management. The bootconfiguration task 512 includes information for starting up and testingthe network device. The network device can also be configured to startupin different configurations and providing different implementations.These can include which functionalities and services are capable ofrunning on the SPC/SMC 500. The high availability task 514 maintains theoperational state of the network device by monitoring the device andmanaging recovery efforts to avoid disruption of service. The resourcemanager tracks and assigns the available resources for sessions anddemands on the network device. This can include load balancing amongdifferent processors and tasks running on the network device. Processescan be distributed across the system to fit the needs of the networkmodel and specific process requirements. For example, most tasks can beconfigured to execute on SPC/SMC 500 or a PAC/PSC 502, while someprocessor intensive tasks can also be performed across multiplePACs/PSCs to utilize multiple CPU resources. Distribution of these tasksis invisible to the user. The switch fabric control 518 controls thecommunication paths in the network device. The controller tasks module520 can manage the tasks among the resources of the networks to provide,for example, VPN services, assign ports, and create, delete, and modifysessions for UE 134.

The PAC/PSC 502 is a high-speed processing card that is designed forpacket processing and the tasks involved with providing various networkfunctionalities on the network device. The PAC/PSC 502 include a memory524, a network processing unit (NPU) 526, a processor 528, a hardwareengine 530, an encryption component 532, a compression component 534,and a filter component 536. Hardware engines 530 can be deployed withthe card to support parallel distributed processing for compression,classification traffic scheduling, forwarding, packet filtering, andstatistics compilations. The components can provide specializeprocessing that can be done more efficiently than using a generalprocessor in some embodiments.

Each PAC/PSC 502 is capable of supporting multiple contexts. The PAC/PSC502 is also capable of running a variety of tasks or modules. PAC/PSC502 a provides routing managers 522 with each covering routing of adifferent domain. PAC/PSC 502 b provides a session manager 538 and anAAA manager 540. The session manager 538 manages one or more sessionsthat correspond to one or more UE 134. A session allows a UE 134 tocommunicate with the network for voice calls and data. The AAA manager540 manages accounting, authentication, and authorization with an AAAserver in the network. PAC/PSC 502 provides a DPI task 542 and asignaling demux 544. The DPI task 542 provides inspection of packetinformation beyond layer 4 for use and analysis by the network device.The signaling demux 544 can provide scalability of services incombination with other modules. PAC/PSC 502 d provides redundancythrough standby tasks 546. Standby tasks 546 store state information andother task information so that the standby task can immediately replacean active task if a card fails or if there is a scheduled event toremove a card.

In some embodiments, the software needed for implementing a process or adatabase includes a high level procedural or an object-orientatedlanguage such as C, C++, C#, Java, or Perl. The software may also beimplemented in assembly language if desired. Packet processingimplemented in a network device can include any processing determined bythe context. For example, packet processing may involve high-level datalink control (HDLC) framing, header compression, and/or encryption. Incertain embodiments, the software is stored on a storage medium ordevice such as read-only memory (ROM), programmable-read-only memory(PROM), electrically erasable programmable-read-only memory (EEPROM),flash memory, or a magnetic disk that is readable by a general orspecial purpose-processing unit to perform the processes described inthis document. The processors can include any microprocessor (single ormultiple core), system on chip (SoC), microcontroller, digital signalprocessor (DSP), graphics processing unit (GPU), or any other integratedcircuit capable of processing instructions such as an x86microprocessor.

Although the present disclosure has been described and illustrated inthe foregoing example embodiments, it is understood that the presentdisclosure has been made only by way of example, and that numerouschanges in the details of implementation of the disclosure may be madewithout departing from the spirit and scope of the disclosure, which islimited only by the claims which follow. Other embodiments are withinthe following claims. For example, the mobility management entity caninclude a direct interface to a packet data network gateway to provideoptimizations to loaded radio access transceivers.

We claim:
 1. A network device comprising: a first interface configuredto communicate with a gateway in a cellular communication network; aradio-related interface configured to communicate with at least one basestation in the cellular communication network, wherein the radio-relatedinterface is a same type of interface used by the at least one basestation to communicate load information with other base stations in theradio access network; and a functionality module configured to: providea mobility management device functionality that communicates controlplane messages between the at least one base station and the gateway andmanages mobility of a plurality of user equipments coupled to the atleast one base station in the cellular communication network;communicate to the at least one base station using the radio-relatedinterface an indication that the functionality module is using aresource block used by the at least one base station, thus causing theat least one base station to regard the functionality module as anotherbase station; obtain load information associated with the at least onebase station and the resource block via the radio-related interface, theload information being sent to the functionality module by the at leastone base station as a result of the at least one base station regardingthe functionality module as another base station; periodically receivethe load information associated with the at least one base station andthe resource block and determine whether the information indicative ofthe load information should be sent to the gateway based on whether atleast one threshold associated with the load information is exceeded;and when the at least one threshold associated with the load informationis exceeded, communicate the information indicative of the loadinformation associated with the at least one base station and theresource block to the gateway to allow the gateway to modify contents ofone or more packet flows destined to pass through the at least one basestation to reduce the load of the at least one base station.
 2. Thenetwork device of claim 1, wherein the functionality module isconfigured to send, over the radio-related interface, a failure messagein response to a handover request message from one of the at least onebase station, thereby avoiding being selected as a candidate for ahandover of the user equipment.
 3. The network device of claim 1,wherein the radio-related interface comprises an X2 interface.
 4. Thenetwork device of claim 3, wherein the functionality module isconfigured to communicate, over the X2 interface, an X2 setup requestmessage and a resource status request message to the at least one basestation to request the load information associated with the at least onebase station.
 5. The network device of claim 1, wherein thefunctionality module is configured to: receive, from the at least onebase station, a resource status response message with the loadinformation associated with the at least one base station, and providethe load information associated with the at least one base station tothe gateway when a predetermined condition is met.
 6. The network deviceof claim 1, wherein the functionality module is configured to receivethe load information associated with the at least one base stationperiodically and prioritize packet flow optimizations at the gatewaybased on the periodic load information.
 7. The network device of claim1, wherein the mobility management device functionality is configured toreceive, from the at least one base station via the radio-relatedinterface, physical resource block load information and determine, fromthe physical resource block load information, the load informationassociated with the at least one base station.
 8. The network device ofclaim 1, wherein the functionality module is configured to establishcommunication with the at least one base station via the radio-relatedinterface using a discovery mechanism used by base stations to discoverother base stations in the radio access network.
 9. The network deviceof claim 8, further comprising a control plane interface configured toprovide control-plane communication with the at least one base station,and wherein the functionality module is configured to communicate withthe at least one base station via the control plane interface to obtainan identity of the at least one base station, and use the identity ofthe at least one base station to establish the communication with the atleast one base station.
 10. The network device of claim 1, wherein thefunctionality module is configured to send, over the radio-relatedinterface, a configuration update message in response to a handoverrequest message from one of the at least one base station, therebyavoiding being selected as a candidate for a handover of the userequipment.
 11. The network device of claim 1, wherein the functionalitymodule is configured to send, to the gateway, instructions toselectively modify packet flows to alleviate loading conditions in theat least one base station.
 12. The network device of claim 11, whereinthe modifications to the packet flows can include one or more of videooptimization, TCP optimization, or HTTP optimization.
 13. The networkdevice of claim 1, wherein the resource block includes a physicalresource block.
 14. The network device of claim 1, wherein thefunctionality module of the network device is further configured to:establish an X2 signaling connection with the at least one base stationover the radio-related interface; manage retransmissions to theplurality of user equipments coupled to the at least one base station;handle a bearer activation/deactivation process; authenticate theplurality of user equipments by communicating with a home subscriberserver; enforce user equipment roaming restrictions; and choose agateway for a user equipment of the plurality of user equipments at theinitial attachment of the user equipment and at the time of an intra-LTEhandover of the user equipment.
 15. A method comprising: communicatingcontrol plane messages, at a mobility management device, between atleast one base station and a gateway in a cellular communication networkand managing, at the mobility management device, mobility of a pluralityof user equipments coupled to the at least one base station in thecellular communication network; communicating, by the mobilitymanagement device, with the at least one base station over aradio-related interface, wherein the radio-related interface is a sametype of interface used by the at least one base station to communicateload information with other base stations in a radio access network,thereby causing the at least one base station to regard the mobilitymanagement device as another base station; indicating, by the mobilitymanagement device, to the at least one station that the mobilitymanagement device is using a resource block used by the at least onebase station, thereby masquerading the mobility management device as abase station; receiving, at the mobility management device, loadinformation associated with the at least one base station and theresource block over the radio-related interface from the at least onebase station, the load information being sent to the mobility managementdevice by the at least one base station as a result of the at least onebase station regarding the mobility management device as another basestation; periodically receiving the load information associated with theat least one base station and the resource block and determine whetherthe information indicative of the load information should be sent to thegateway based on whether at least one threshold associated with the loadinformation is exceeded; and when the at least one threshold associatedwith the load information is exceeded, communicating the informationindicative of the load information associated with the at least one basestation and the resource block to the gateway to allow the gateway tomodify contents of one or more packet flows destined to pass through theat least one base station to reduce the load of the at least one basestation.
 16. The method of claim 15, further comprising sending, overthe radio-related interface, a failure message in response to a handoverrequest message from one of the at least one base station, therebyavoiding being selected as a candidate for a handover.
 17. The method ofclaim 15, further comprising: receiving a resource status responsemessage from the at least one base station with the load information;and communicating the load information to the gateway when a thresholdis met.
 18. The method of claim 15, further comprising receivingperiodic load information updates and prioritizing packet flowoptimizations at the gateway based on the periodic base station loadinformation.
 19. A non-transitory computer readable medium havingexecutable instructions operable to cause a processor of a mobilitymanagement device to: communicate control plane messages between atleast one base station and a gateway in a cellular communication networkand manage mobility of a plurality of user equipments coupled to the atleast one base station in the cellular communication network;communicate with the at least one base station over a radio-relatedinterface, wherein the radio-related interface is a same type ofinterface used by the at least one base station to communicate loadinformation with other base stations in a radio access network, therebycausing the at least one base station to regard the mobility managementdevice as another base station; indicate to the at least one basestation that the mobility management device is using a resource blockused by the at least one base station, thereby masquerading the mobilitymanagement device as a base station; receive load information associatedwith the at least one base station and the resource block over theradio-related interface from the at least one base station, the loadinformation being sent to the mobility management device by the at leastone base station as a result of the at least one base station regardingthe mobility management device as another base station; periodicallyreceive the load information associated with the at least one basestation and the resource block and determine whether the informationindicative of the load information should be sent to the gateway basedon whether at least one threshold associated with the load informationis exceeded; and when the at least one threshold associated with theload information is exceeded, communicate the information indicative ofthe load information associated with the at least one base station andthe resource block to the gateway to allow the gateway to modifycontents of one or more packet flows destined to pass through the atleast one base station to reduce the load of the at least one basestation.
 20. The non-transitory computer readable medium of claim 19,wherein the instructions are further operable to cause the processor tosend a failure message in response to a handover request message fromone of the at least one base station, thereby avoiding being selected asa candidate for a handover.
 21. The non-transitory computer readablemedium of claim 19, wherein the instructions are further operable tocause the processor to send load information regarding a particular basestation to a corresponding gateway to begin packet flow optimizations tothe particular base station when a scalar threshold is exceeded from thebase station load information.